This invention relates to a method for attaching a porous augment to an orthopedic implant.
Orthopedic implant systems are available for joint replacement surgeries of the hip, knee, shoulder and other articular joints. Orthopedic implants are also available for non-articulating orthopedic applications, which may include trauma and intercalary surgeries. Overall, these implant systems may include articulating resurfacing components, segmental elements, stems, offsets and augments. First generation orthopedic stem implants were monolithic, manufactured from cobalt chrome or titanium materials, and configured with either a round or square longitudinal stem element. The first generation orthopedic implants utilized bone cement for fixation within the body.
Later generations of implant designs introduced porous ingrowth surface technology. An example of this porous ingrowth surface technology is described in U.S. Pat. No. 5,192,324. Briefly, this patent describes a porous coating for bone ingrowth or interlocking with bone cement. Orthopedic systems with porous ingrowth technology provide clinical benefits including improved soft tissue fixation, integration and stability.
As technology continues to evolve, porous ingrowth surfaces are manufactured from advanced machining techniques such as the laser produced porous structure described in U.S. Pat. No. 7,537,664 and the laser produced porous surface describe in U.S. Patent Application 2006/0147332, the disclosures of which are incorporated herein by reference.
A challenge with the advanced porous ingrowth surface, such as the laser produced porous surface, is the ability to assemble the augment, stem or any segmental implants without damaging the ingrowth surface. Therefore, a need exists for implants with structural configurations specifically designed to allow for assembly of implant components without while preserving the integrity of the porous ingrowth surface.